JP6706754B2 - Power converter - Google Patents

Description

The present invention relates to a power conversion device that converts direct-current power obtained from an external direct-current power supply such as a solar cell into alternating-current power, and particularly to a power conversion device having a moisture intrusion suppression configuration.

A power conversion device for a photovoltaic power generation system (called a power conditioner) has a casing, in which a DC power generated by a solar cell is input as a power conversion circuit to boost the voltage by a booster circuit, which is effectively connected to a commercial power system. The circuit accommodates a predetermined AC power that is synchronized with the inverter circuit and converts the converted AC power into a commercial power system. This power conversion circuit is equipped with heat-generating components such as semiconductor switching elements and reactors. The heat generated by these components is mounted in a heat-conducting state on the substrate part of the heat sink and is radiated from the heat radiation fins of the heat sink. There is (Patent Document 1).

JP2012-164878A

Such a power conversion device has an outdoor installation type and an indoor installation type, but in the indoor installation type,
As an unobtrusive place, it is often installed in a room adjacent to the bathroom, for example, in the upper part of the wall of a dressing room or washroom. Usually, a mirror or a washbasin with a mirror is installed on the wall opposite the wall between the dressing room or washroom and the bathroom, so the power converter is located above the bathroom-side wall in the dressing room or washroom. It is installed. For this reason, when the entrance door of the bathroom is opened, steam (mixed phase of water droplets and water vapor that has condensed due to contact with the outside air and the temperature of the gas drops) flows out into the dressing room or washroom at a time, and this is the power conversion device. Get on.

The power conversion device has various electric circuits housed in a housing as disclosed in Japanese Patent Laid-Open No. 2004-242242. Also,
There is a form in which a heat sink is housed in the housing. In any of the above forms, an air inflow portion formed by a number of small holes or slits is provided on the lower wall of the housing as an air circulation portion for promoting heat dissipation of electric circuit components and heat sinks inside the housing, and The wall is provided with an air outflow portion formed by many small holes and slits.

In the form in which direct current is input from the solar power generation system to the power converter, the power converter operates normally during the daytime when sunlight appears, and the temperature inside the housing of the power converter rises. An ascending airflow that flows upward from below is formed between the many fins of
The heat dissipation of electric circuit parts is promoted. On the other hand, since the power conversion device does not perform the power conversion operation at night when sunlight is not emitted, the temperature inside the housing of the power conversion device is low and the temperature of the heat sink is also low. Therefore, it is difficult to form an updraft that positively flows from the air inflow portion of the lower wall toward the air outflow portion of the upper wall.

Even when the power converter is operating, or when the power converter is stopped, steam that flows out of the bathroom to the dressing room or washroom at one time when the entrance door of the bathroom is opened is mainly used in the power converter. There is a concern that the air will flow into the casing from the air inflow portion of the lower wall of the casing and will adhere to the electric circuit components inside the casing, resulting in deterioration or electric leakage of these electric circuit components.

According to the present invention, when the power conversion device is operating, promotion of heat dissipation of the electric circuit components in the housing is ensured, and steam temporarily flowing out when the door of the bathroom is opened flows into the housing of the power conversion device. It is an object of the present invention to provide a technique capable of preventing an electric circuit component in a housing from being deteriorated or leaking, which is likely to be caused by steam, by providing an obstacle member so as to be difficult to perform.

In the power conversion device of the present invention, a power conversion circuit that converts direct-current power obtained from a direct-current power source such as a solar cell into alternating-current power is housed in a housing, and an air inflow portion is provided on a lower wall of the housing, In a power conversion device having an air outlet on the upper wall of the housing,
A member facing the lower wall is provided below the air inflow portion with a gap.

In another power converter of the present invention, a power conversion circuit for converting DC power obtained from a DC power source such as a solar cell into AC power is housed in a housing, and an air inflow portion is provided on a lower wall of the housing. In the power conversion device including an air outlet on the upper wall of the housing, a lower plate facing the lower wall with a space below the air inlet, and one of left and right sides of the air inlet. A member having a lateral plate extending from the lower wall to the lower plate is provided, and the lateral plate is foldably provided on the lower plate.

According to the present invention, when the power conversion device is operating, promotion of heat dissipation of the electric circuit components in the housing is ensured, and when temporary steam outflow occurs, such as when the door of the bathroom is opened. Is a member that blocks steam and prevents steam from entering the air inflow part, making it difficult for steam to flow into the casing of the power conversion device. It is possible to suppress the deterioration and electric leakage of the electric circuit parts in the housing due to the steam flowing out from the casing.

It is explanatory drawing of the front view which shows the state when the cover of the power converter device which concerns on this invention is opened. It is explanatory drawing by the cross section of the power converter device which concerns on this invention. It is a circuit block diagram of the power converter device which concerns on this invention. It is a top view of the power converter device which concerns on this invention. It is a bottom view of the power converter device which concerns on this invention. It is a front perspective view of the state which attached the member to the power converter concerning the present invention. It is a perspective view of the member concerning the present invention. It is a bottom view of the power converter device which concerns on other embodiment of this invention. FIG. 7 is a diagram showing a state in which the mounting columns of the member according to the present invention are locked. It is sectional drawing which shows the state which the attachment pillar of the member which concerns on this invention locked. It is a member which concerns on other embodiment of this invention, (a) is a front view of a member, (b) is a top view of a member.

In the present embodiment, a power conversion circuit that converts direct-current power obtained from an external direct-current power source such as a solar cell into alternating-current power is housed in a housing, and an air inflow portion is provided on a lower wall of the housing, and the housing In a power converter having an air outlet on the upper wall of
In the power conversion device, a member facing the lower wall is provided below the air inflow portion with a gap.
The embodiment will be described below with reference to the drawings. In the embodiment, the power conversion circuit and the heat sink are housed in the housing.

As shown in FIGS. 1 and 2, the power conversion device 1 according to the present embodiment is an electric power conversion circuit INV that converts direct-current power obtained from an external direct-current power source such as a solar cell PV into alternating-current power. The circuit component 6 is housed in the housing 2. The casing 2 is composed of a metal main body 3 and a metal lid 4, and the main body 3 is composed of a color steel plate with one surface of a steel plate being color-coated, with the color-coated surface being the outside. A rectangular box surrounded by the upper wall 3A, the lower wall 3B, the left wall 3C, the right wall 3D, and the back wall 3E and having a front opening 3F is formed. The lid 4 is made of a color steel plate with one surface of which is color-painted, and the color-coated surface is the outside, and is detachably attached to the body 3 with a mounting screw so as to close the front opening 3F of the body 3. .. In addition,
The lid 4 can be opened and closed by a hinge on the left wall 3C or the right wall 3D of the main body 3.

FIG. 3 shows the configuration of the power conversion circuit INV. The power conversion circuit INV is a solar cell P.
The DC power generated by V is supplied to the DC reactor L1, the switching element S1, and the diode D.
1. A booster circuit BS including a smoothing capacitor C1 boosts the voltage to a predetermined voltage, and the power boosted by the booster circuit BS is synchronized with a frequency of a commercial power system GRID by a DC/AC converter circuit DA including a plurality of switching elements S2. Is converted to a sine wave alternating current, and is output to the commercial power system GRID via the relay contact RY in a state where the high frequency component is cut or sufficiently attenuated by the low pass filter LPF including the AC reactor L2 and the capacitor C2. .. Boost circuit BS
The operation of the DC/AC conversion circuit DA and the relay contact RY is controlled by the control circuit CP.

A power conversion circuit INV is housed in the main body 3, and as shown in FIG. 2, a chassis 5 for mounting a plurality of electric circuit components 6 constituting the power conversion circuit INV is provided in the main body 3 with a back wall 3E. It is attached to the back wall 3E at a predetermined interval so as to be arranged in parallel.
Of the electrical components that make up the power conversion circuit INV, a main electrical circuit component 6 other than large components such as the DC reactor L1, the AC reactor L2, and the capacitors C1 and C2.
Are arranged on the main board 7 formed of a printed wiring board having a large plane area, and the DC reactor L1, the AC reactor L2, the capacitor C1 and the capacitor C2, etc. are electrically connected to the wiring pattern formed on the main board 7. Connected to.

As shown in FIGS. 1 and 2, in the main body 3, a reactor accommodating portion 9 is provided vertically adjacent to the heat sink 8. The reactor L1 for direct current and the reactor L2 for alternating current in the power conversion circuit INV are attached to the front surface side of the support plate 10 which is attached to the back wall 3E with a fixture such as a screw in the reactor accommodating portion 9, and to a fixture such as a screw. And install it vertically.

As shown in FIGS. 1 and 2, in the main body 3, a terminal block 11 is provided on the side opposite to the reactor housing portion 9.
In order to arrange the terminals, a flat terminal block placement portion 5A is formed by recessing a part of the chassis 5 to the rear, and the terminal block 11 is attached thereto.

The terminal block 11 is a connection terminal between the power conversion circuit INV and the solar cell PV, and the power conversion circuit INV.
And a commercial power grid GRID, including a connection terminal, a ground terminal, and a self-standing terminal, and the connection line 13 between the terminal block 11 and the power conversion circuit INV can be visually recognized from a part of the window of the chassis 5.

When the commercial power grid GRID becomes inoperable due to a disaster or the like, the self-sustaining terminal is provided with an electric appliance in a house by the AC power generated by the solar cell PV and converted by the power conversion circuit INV. It is for connecting to an emergency outlet for operation.

In the back wall 3E and the lower wall 3B of the main body 3, wirings for the solar cell PV, the commercial power grid GRID, and an emergency outlet are connected to the terminal block 11, so that the wiring opening 12 is formed.
Is formed corresponding to.

Each of the capacitors C1 and C2 has a single structure or a group of a plurality of small capacitors, and these are arranged in a space above the terminal block 11.

In the power conversion circuit INV, the switching elements S1 and S2 generate heat and reach a high temperature. Therefore, in order to dissipate the heat generation, the switching elements S1 and S2 are modularized in a form of being housed in one or a separate package. This is called IPM (Intelligent Power Module).

The IPM is attached to a heat sink 8 having good heat conductivity such as aluminum. As shown in FIG. 2, the heat sink 8 has a board portion 8A and a plurality of heat radiating fins 8B extending from the board portion 8A in parallel in the left-right direction. It is attached to the back wall 3E with a fixing tool such as a screw so as to be located between the chassis 5 and the back wall 3E in the main body 3 while facing the opening 3E1 formed in the back wall 3E. An air inflow portion 15 is provided on a lower wall 3B of the main body 3 which is a lower wall of the housing 2, and an air outflow portion 16 is provided on an upper wall 3A of the main body 3 which is an upper wall of the housing 2.

As shown in FIG. 5, the air inflow portion 15 flows between the first air inflow hole 15A formed of a large number of small holes and the heat radiation fin 8B for heat radiation of the electric circuit components of the power conversion circuit INV. And a second air inflow hole 15B formed by a large number of slits.
In addition, as shown in FIG. 4, the air outflow portion 16 flows out from between the first air outflow hole 16A formed by a large number of small holes and the heat radiation fin 8B for heat radiation of the electric circuit components of the power conversion circuit INV. And a second air outflow hole 16B formed by a number of slits for the air to be used.

The heat radiation surface made of metal such as aluminum on the back side of the IPM is attached to the front surface of the substrate portion 8A of the heat sink 8 by a fixing member such as a screw in a heat conductive state.
The air is transmitted from A to the radiation fins 8B and is radiated by the air rising between the radiation fins 8B.

If the diode D1 also generates a large amount of heat, like the IPM, it is modularized in the form of being housed in a package and mounted on the front surface of the substrate portion 8A of the heat sink 8 in a heat conductive state with a fixing tool such as a screw. If the diode D1 is included in the IPM and packaged, the work of attaching the heat sink 8 to the substrate portion 8A becomes easy.

The power conversion circuit INV includes an input-side current sensor CT1 that detects an input current from the solar cell PV to the power conversion circuit INV, and an output-side current sensor CT2 that detects an output current of the power conversion circuit INV. The input side current sensor CT1 and the output side current sensor CT2 are Hall element type current sensors that can be used for detection of both direct current and alternating current in order to share them, and are a sub-board 71 attached to the main board 7. , 72, respectively.

FIG. 6 shows the power conversion device 1 provided with the member 17. An operation window facing the control panel unit 30 arranged in the main body 3 is provided in the lower portion of the front surface (front surface) of the lid body 4. The control panel unit 30 is provided with a display unit for displaying the generated power and integrated power of the power converter 1, an operation and stop switch operation unit, and the like.

As shown in FIG. 6, the member 17 is provided below the air inflow portion 15 with a space therebetween and the lower wall 3 is provided.
A lower cover plate 18 (lower plate) that faces B and covers the air inflow portion 15 from below;
And a side cover plate 19 (side plate) extending from the lower wall (side) to the lower wall plate (side). In the illustrated case, the entrance of the bathroom is located on the left side of the power conversion device 1, and thus the side cover plate 19 covers the left side of the air inflow part 15.

As one specific configuration of the member 17, the member 17 is made of synthetic resin, the lower cover plate 18 and the side cover plate 19 are flat plates, and the lower end of the side cover plate 19 has a lower cover plate 18 The lower cover plate 18 and the side cover plate 19 are in contact with the upper surface of the above, and serve as a barrier for steam to flow into the air inflow part 15 from the left side of the air inflow part 15 (block the steam).

In this case, in plan view, the plane area of the lower cover plate 18 is equal to or slightly larger than the plane area of the entire air inflow portion 15, and the lower cover plate 18 covers the entire air inflow portion 15. That is, the size of the member 17 including the lower cover plate 18 and the side cover plate 19 is such that the member 17 including the lower cover plate 18 and the side cover plate 19 does not interfere in the mounted state. The size is within the range of the lower wall 3B. The lower cover plate 18 need not fit in the lower wall 3B in a plan view, and when the side cover plate 19 is not used, the lower cover plate 1
8 may project from the lower wall 3B in the direction of the entrance/exit of the bathroom.

Since the member 17 is wide open in this way, the electric circuit component 6 in the housing 2 generates heat when the power converter 1 is operating, and the heat causes the temperature of the heat sink 8 to rise. Therefore, the air around the power conversion device 1 flows into the housing 2 from the air inflow part 15 and flows out from the air outflow part 16 to be promoted. For this reason, when the power conversion device 1 is operating, the heat dissipation of the electric circuit components 6 in the housing 2 is favorably performed.
In the illustrated one, the right side of the air inflow part 15, which is the side far from the entrance/exit of the bathroom, is open,
The inflow of air into the air inflow portion 15 is promoted also from this portion.

On the other hand, in the path through which steam flowing out of the entrance and exit of the bathroom flows into the air inflow part 15,
Since the lower cover plate 18 and the side cover plate 19 are present, they serve as a barrier to the steam flow, and the steam is prevented from flowing into the air inflow portion 15 at one time, and the electric circuit component 6 in the housing 2 is prevented. Can be protected.

The member 17 may be fixed to the main body 3 by a fixture such as a screw, but the restraining function of the member 17 is exerted regardless of whether the position with respect to the entrance and exit of the bathroom is on the left or right of the air inflow part 15. For this reason, it is easy to change the position of the side cover plate 19 between the state of being located on the left side and the state of being located on the right side. Therefore, the member 17 is configured to be attachable to and detachable from the main body 3 so that the attachment position of the member 17 can be inverted 180 degrees with respect to the main body 3.

As one of the configurations, as shown in FIGS. 6 and 7, mounting struts 20A and 20B are arranged in front and back on the left and right portions of the lower cover plate 18. Left or right mounting column 20A, 20B
A cover plate 20C is attached to the. In the illustrated example, a cover plate 20C is attached to the left-side mounting columns 20A and 20B so as to be applied when a bathroom entrance exists on the left side of the power conversion device 1. The mounting columns 20A and 20B have outwardly hooked locking portions 2 at their tips.
1 is formed and the elasticity of the mounting columns 20A and 20B is used to elastically lock the locking portions 21 to the left and right end portions of the air inflow portion 15, so that the member 17 is attached to and detached from the air inflow portion 15. Supported as possible.

In this way, the locking portion 21 is disengaged from the end of the air inflow portion 15 so that the side cover plate 19 is located at the entrance/exit side of the bathroom, and the member 17 is rotated 180 degrees with respect to the main body 3. The locking portion 21 can be elastically locked to the end of the air inflow portion 15 by utilizing the elasticity of the mounting columns 20A and 20B.

Also, the tip ends of the mounting columns 20A and 20B are screwed to the lower wall 3B of the main body 3,
In a state where the member 17 is rotated 180 degrees with respect to the main body 3, the mounting column 20A is again screwed,
A method of fixing the tip of 20B to the lower wall 3B of the main body 3 may be used.

As still another configuration, the side cover plate 19 has a configuration in which the cover plate 20C is detachably attached to the front and rear mounting columns 20A and 20B arranged side by side, and the cover plate 20C attached to the left side mounting columns 20A and 20B is used. A method of removing and attaching to the right mounting columns 20A and 20B may be used.

The air inflow portion 15 may be divided into a first air inflow hole 15A and a second air inflow hole 15B as shown in FIGS. 5 and 6, but as shown in FIG. It may be in the form of one rectangular air inflow hole penetratingly formed in 3B. In either form, an air filter 22 is attached to the inner peripheral edge of the lower wall 3B of the main body 3 so as to cover the entire air inflow part 15 as a suction removal of dust in the air flowing into the air inflow part 15. Be done.

Also in the case where the air inflow portion 15 is formed as one air inflow hole as shown in FIG. 8, the member 17 uses the elasticity of the left and right mounting columns 20A and 20B as shown in FIGS. 9 and 10. Then, the locking portion 21 is elastically locked to the left and right end portions of the air inflow portion 15, so that the member 17 is detachably supported by the air inflow portion 15. The left and right mounting columns 20A and 20B may be detachably attached to the lower wall 3B of the main body 3 with screws.

When the power conversion device 1 is installed in a washroom or the like adjacent to the bathroom, the member 17 is effective in protecting the power conversion device 1 from steam flowing out from the bathroom, but in a room away from the bathroom, a corridor, or the like. When the power conversion device 1 is installed on the wall, the member 17 is not necessary. Therefore, in addition to the above configuration, FIG. 11 shows one configuration for making it possible to easily attach and detach the member 17 to and from the power conversion device 1.

In FIG. 11, as shown in (b), the side cover plate 19 and the mounting columns 20A and 20B on the opposite side of the side cover plate 19 can be folded with respect to the lower cover plate 18 by the shaft mechanism 23. Figure 1
If the side cover plate 19 and the mounting struts 20A and 20B on the opposite side thereof are provided on the shaft mechanism 23 so as to hold the state of standing up from the lower cover plate 18 as in 1 (a), Can stand up.

In the above embodiment, the lower cover plate 18 and the side cover plate 19 are separately formed, but the lower cover plate 18 and the side cover plate 19 are formed of an integral flexible plate member. , The side cover plate 19 to the lower cover plate 1
It may be configured to be foldable into eight.

Although a solar cell was taken as the external DC power source, a fuel cell, a wind power generator, a wave power generator, or the like can also be applied.

1 Power Converter 2 Housing 3 Main Body 3A Upper Wall 3B Lower Wall 4 Lid 6 Electric Circuit Parts 8 Heat Sink 15 Air Inflow Portion 16 Air Outflow Portion 17 Member 18 Lower Cover Plate 19 Side Cover Plate 20A Mounting Post 20B Mounting Post 20C cover plate INV power conversion circuit PV solar cell

Claims (1)

A power conversion circuit that converts direct-current power obtained from a direct-current power source such as a solar cell into alternating-current power is housed in the housing, the lower wall of the housing is provided with an air inflow portion, and the upper wall of the housing is outflowing air. In a power conversion device including a unit,
A member having a lower plate facing the lower wall with a space below the air inflow portion, and a side plate extending from the lower wall on one of the left and right sides of the air inflow portion to the lower plate, The power conversion device, wherein the side plate is foldably provided on the lower plate.

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